Wally wrote:

Just been here...

http://www.nch.com.au/tonegen/index.html

...and downloaded their tone generator prog to have a play. Turns out that
you can set up tones and save them as wave files, so I duly made a test
tone CD with the following frequencies played as 0dB sine waves lasting a
few seconds each...

100, 90, 80, 70, 60, 50, 40, 35, 30, 20, 20

I duly fired it onto the hifi and got the following impressions of volume
for each...

100 - 5
90 - 5+
80 - 5
70 - 4+
60 - 4
50 - 3+
40 - 2
35 - 1
30 - 1
25 - 2
20 - 1-

90Hz came across as a distinct peak amongst the upper frequencies which
otherwise seem to lose volume smoothly from 100 to 50Hz. There was a big
drop in volume going from 50 to 40Hz. 25Hz was a surprise peak at the
lower end - not mega loud, but clear and present compared to the other low
tones, which seemed to require listening for. 20Hz is there but barely
audible.


Apart from the 90Hz peak this is not a million miles away from the response
of the average human ear so the speaker may in fact be better than it
sounds. The 25Hz surprise may well be a room resonance artifact although
you would need a rather big room to get a large peak. Whereabouts was the
speaker when you did this test?

Ian